Shingle-machine spur-roll ratchet



mmh 31. 1925. 1 1,531,825

. H. B. WEBB SHINGLE MACHINE SPUR ROLL RATCHET Filed OC'b. 4, 1925 Patented Mar. 31, i925.

' UNM-Eo sTArEs restera A Parra-r 'orali-ice... q-

sHINeLE-MaoH-rnn eren-nona' RATCHET'.'

'Appiicauon 1aed` october 4,. lef/:aj serial. No; 666,652'.

To all 107mm it may conce/mt:

Be it known that I,.HARRY BARma'r'r WEBB, a subject of thel King olf GreatBritain, and a. resident of the city' of New lilest'minster, in the vlProvinccof British Columbia, Canada, haveA invented certain. new and useful Improvementsl iir Shingle-Machine .Spun-Roll. Ratoliets, ot which the `following is a, specification- My inventioni relates to improvements in vratchetsfoi" use in the operation oil the spur rolls shingle machines, although the iiivention may he employed with equael facility and advantagetor other anal'a'gous purposes, and the object of my invention, is to provide a ratchet which while of light,l compact, and simple construction is yet strong andi efficient, possessing the maximumwearing surface within the limits et its convenient size without detracting from: its practicaloility,

and in which a very fine adjustment of feed may hel attained', reducing backlash to a minimum andfeliminating unduey slack-ness and wear. A further object is to. devise an eliicient. and practical internal ratchet, that is, one which` is adapted tol loeY completely enclosed so that it isA protected froml dust and can loe run in an oil bath so that it is smooth 1in operation` andI is maintained in perfect working order with the minimum.

oit attention and`v repair.

lattain these' objects hy the construction illustrated in the accompanying dra-wings in which Fig'. 1 is a side elevation of the ratchet.y

Fig.l 2 is an edge View.

Fig. 3l isa side elevationl with one` side ofthe coverrcmoved'. 1

Fig. t is a cross sectional View through the line 1 -4t ofFig. 3. 1 Fig. 5 is a slightly reduced cross sectional view of the pafwly disc. H i

Fig. G is a view illustrating the *ratchet mounted on a spur roll` Fig. 7 is a View showing the ratchet and its associated hell crank and;l lever.

Similar figures of reference indicate similar parts throughout the several views.

The device consists or' an annular plate disc l having a central bore 2 extending through concentric bosses 3 and 4 on each side of the disc, thc herev 2 being adapted to he fitted on and secured to the end of the spur roll shaft, as indicated in Figs. 6 and tafken 7 av plurality of radially extending equidist-a-ntly spaced slots, vindnicated by the numenalv 5', are cut in' the disc, extending to within: a short distance of the loore 2', and: in these* slots arer slid-ably. mounted vfor inward andy outward movement 'paiwls (2.7,. 8, `9, 1,0 and 111i respectivelthe 'oute'rj ends oi which ame ratchet-tooth shaped, and` project normally a. 'designedv .amount beyondy the peripheralcdgeofthe disc..` -Two holes, l-2; and laare" provided' in the lower. end of each pawl; and. i'n the holes are disposed' springs,

.114tand 151respectivelwthe lower ends of' which springs rest on theb-ottom. ot their respective s-lots, as sliowne'in` Figs: 3 and'fl, from which it will loe seen that the pavvls are resiliently` supported and spring-pressed withiini the slotsa\nd in order'to preventside play -o'j the 4pawls, annular'. plate rings: I6 f and 17'. are secured by'suitalo'le screws? 18' t-o the'disc oni each sidevof it, between which plate'sth'e pawls` are: movable..

192 and 20 indicateI )thrv l"opposite side plates of' a coverformedi as sho-wn in F ig.k l

and' indicated generally bythe numeral 21',

completely enclosingithe. disc andy the pawls, which. cover; has concentric. side bosses 22 andi 231 through. which extendv freelyv the bosses 3 and' 4t ot the disc,l sothat the cover 2l is.' thus"Y rotatably* mountedl on the disc.

The' twoi-si'de;v plates ot the'cover are flanged inwardly' asf shown'. and' are holted togetliier by bolts=24y in: order to he readily assembled and disassembled, and rigidlysecured! tol the inner periphery of the cover plate 20.is a ring 25. the' inner periphery ofwhi'chring is provided with a1 plurality of ratchet teeth 26,. these teeth hein-g 'spa-ced equidi'stantly around" the ringy and of a1 designed ,'pitch,

Vfrom which it will!` beiseen that thevv cover is= provided with an internal-'ratchetftoothed gearvand withthis internal gear the pawls however, being engaged at atimegas shown in Fig.l 3. y

The cover'2'1 'is formed with a pau" of apertured lugs 27 and' 28, to one o'lwhic-h,

according as to whetherthe' ratchet is `forv the upper spur rolll or' thel 'lower one, yis yconnected the-end 'of ai lever 29 the opposite length, as at 32 and 33, in each of which grooves there may be placed if desired a ring of wick to prevent oil leakage from the cover and render it dust proof.

The operation of ratchet devices is generally well-known and require no extended description beyond stating that rocking of the bell crank 30 by the set works mechanism 31 partially rotates the cover 21 and consequently the internal gear 26 and as there is normallyy one of lthe pawls mentioned in engagement with the gear the disc 1, on one stroke of the cover, is also partially rotated, thus partially rotating the spur roll shaft 34, since the disc 1 is secured to the shaft. On the return stroke of the cover, of

course, no movement of the disc takes place,-

as the pawls are depressed against their respective springs and merely ride over the gear until the end of the stroke when one of the pawls then drops into engagement with a tooth, being pressed outwardly by its springs 14 and 15.

It will be noted,rhowever, that as opposed to other ratchets in common use in which there is always present a considerable amount of lost-motion and backlash, resulting in irregularities in the spur roll feed and consequently irregularity in' the cutting of the shingles, this defect is practically elimiv nated in the ratchet described in the forego ing. since the multiplicity of pawls renders it unnecessary for the cover to move through a distance fractionally greater than the pitch of the teeth before driving engagement is effected between the pawl and the gear, as is necessary in one pawl ratchets in which if the pawl does not enga-ge the tooth on account of undue slacknes's or other reasonsA that particular stroke is lostand the resultant lost motion renders the ratchet very ineicient; in this present case, when six pawls are used, at any point of the cover movement fractionally greater than onesixth of the pitch one of the pawls must necessarily engage the gear so that the possibility of excessive lostmotion is entirely elimi nated and thus great regularity of the spur roll feed is obtained andvuniformity of the shingles positively assured. It should be pointed o-ut that any practical number of pawls may be employed and by increasing the number the adjustment may be made as fine as may be desired and lost motion lor lslackness reduced to the absolute minimum.

The construction illustrated enables a ratchet to be yprovided which is not heavy or cumbersome but which on the other hand is extremely light when thev purpose for which it is or may be employed is considered and this advantage is attained without sacrilicing strength, durability, or etiiciency, trom which it willbe seen that I have devised a ratchet which is of great utility and advantage wherever it may be used and particularly in co-operat-ion with the spur rolls of shingle machines.

l/Vhat I claim as my invention is z- 1. A ratchet comprising an annular plate disc having a central bore extending through concentric side bosses and a plurality of radially extending slots in each of which is slidably mounted a pawl, each said pawl projecting beyond the disc periphery, springs in each slot on which its respective pawl is seated, annular plate rings secured to the disc on its opposite sides forming'side walls for the slots, and azcover in which said vdisc is enclosed provided with an internal ratchettoothed gear with which said pawls one at a time are engageable, said cover having concentric side bosses in which the disc bosses are freely mounted.

2. A ratchet comprising a disc provided with spring pressed pawls projecting radially from it and having annular plate ringsl secured to it on opposite sides forming side walls between which said pawls operate, and a cover in which said disc is enclosed formed in two portions detachably connected to gether one of which portions is provided with an internal ratchet-toothed gear with which said pawls one ata time areengageable.

3. A ratchet comprismgan annular plate disc having a central bore extending through concentric side bosses and a plurality of radially extending slots in` each of which is slidably mounted a pawl, each said pawl projecting beyond the disc periphery, springsiu each slot on which its respective pawl is seated, annular' plate rings? secured to the disc on its opposite sides forming sidewalls for the slots, and a cover in which said'disc is enclosed formed in two portions detachably connected together one of whichis provided with an internal ratchet-toothedgear with which said pawlsv one at a time are eng'ageable, said cover-having concentric silf bosses in which the .y disc bossesA are freely mounted.

Dated at Vancouver, B. C., this 10th day of September, 1923.

HARRY BARRETT WEBB 

